"I'm sure you will understand that this has been a very difficult and exhausting ordeal for Warren," his brother Wayne Rodwell said at the same briefing. "It has also been a difficult time for his family."

"He is delighted to be free," he said. "He has, however, lost a lot of weight and is exhausted. He will need special medical support as well as time and space to recover."

Reports in the Australian and Philippine news media suggested that Rodwell's family had paid a ransom worth nearly $100,000 in return for his release.

His brother and sister declined to field questions at the news conference in Manila.

The Philippine government on Sunday said that its policy is not to pay ransoms for victims of kidnappings, the official Philippines News Agency reported.

"Having said that, we have no information or confirmation on that alleged ransom that was paid," Deputy Presidential Spokesperson Abigail Valte said.

A separatist group

Abu Sayyaf, which wants to establish a separate state for the Philippines' minority Muslim population, has been blamed for several terrorist attacks, including the bombing of a ferry in 2004 that left about 130 people dead, as well as previous kidnappings.

Although the Philippine government agreed a preliminary peace deal last year with the Moro Islamic Liberation Front, a leading rebel group in the country's restive south, some extremists are still active.

"We wish the Philippine police every success in tracking down the group that took Warren from his home," Cappello said.

"We hope they will be brought to justice, so others don't have to experience what Warren has just been through," she added.

The Australian government welcomed Rodwell's release over the weekend, paying tribute to the Philippine government agencies that try to tackle kidnapping cases.

Prime Minister Julia Gillard also acknowledged what his relatives had gone through.

"Mr. Rodwell's family have shown a great deal of courage and stoicism in what has been a tremendously difficult situation," she said.